Do widowed queens who continued as regents after their husbands’ deaths not count?
Surely there must be a few of these from much earlier periods. Prabhāvatī Guptā is one. Another from further afield might be Kulaprabhāvatī, known from a fifth-century Cambodian inscription that seems to have been composed after her husband’s death (K. 875, Journal of the Greater India Society IV, p.117).
Dominic Goodall